This invention relates to the field of electromagnetic compliance (EMC) testing and, more particularly, to an adaptor for use with a magnetic clamp device for grounding EMC electrical test apparatus in a quick and efficient manner.
Electromagnetic compliance testing is typically done in a specially constructed room having a metal floor which is connected to earth ground. The test apparatus must itself be grounded and for that purpose typically is provided with an outer conductive flange which is placed flat against the metal floor and secured thereto. In the past, such grounding has been accomplished either by using a conductive copper tape or by providing a direct mechanical connection. While effective, these ways of grounding the test apparatus have proven to be time consuming and the use of copper tape has also proven to cause injuries to test personnel. It would therefore be desirable to have a device which can be used to quickly and effectively ground the conductive flange of the test apparatus to the ground plane (i.e., the metal floor).
In U.S. patent application Ser. No. 09/726,182, filed Nov. 29, 2000, (now U.S. Pat. No. 612,831,766) and assigned to the assignee of this invention, there is disclosed a magnetic clamp device which allows the grounding of a conductive flange of test apparatus to a metallic ground plane in a quick and efficient manner. The device includes a top plate and a spring-loaded bar secured to the top plate. The bar is straddled by a pair of magnet assemblies so that when the bar is placed over-the conductive flange of the test apparatus, the magnet assemblies straddle the flange and are magnetically secured to the ground plane, with the spring-loaded bar pressing the flange into conductive engagement with the ground plane. However, some test apparatus is manufactured with flanges which do not extend far enough away from the test apparatus enclosure to be properly grounded by this magnetic clamp device. It would therefore be desirable to have an adaptor which can be used with the magnetic clamp device and which accommodates short flanges.
According to the present invention, there is provided an adaptor for use with a magnetic clamp device to ground electrical apparatus to a metallic ground plane, wherein the electrical apparatus includes an enclosure and a conductive ground plate extending outwardly from a side of the enclosure so as to form a flange. The adaptor comprises a conductive baseplate and at least one clamp member secured to the baseplate for clamping the flange to the baseplate. The baseplate has a planar region dimensioned to cooperate with the magnetic clamp device so as to be grounded to the ground plane.